Image display device

Abstract

An image display device according to the present invention comprises a back panel on which a plurality of pixels each having a thin film electron emitter are arranged two-dimensionally, a front panel disposed opposite the back panel on which phosphor layer is formed, and a sealing frame with which the back panel and the front panel are fixed mutually to seal the plurality of pixels and the phosphor layer in a space enclosed by the back panel, the front panel, and the sealing frame, and is characterized in that double-layered signal lines each electrically connected to a group of the plurality of pixels are formed on the back panel, each of the double-layered signal lines consists of a lower-level electrode made from a silver paste and an upper-level electrode covering at least a part of the lower-level electrode laminated in this order on the back panel. The lower-level electrode is shaped e.g. by coating a groove formed in a surface of the back panel with the silver paste, and a surface of the upper-level electrode is used e.g. for an electrode of the thin film electron emitter, also. According to the configuration, the present invention reduces wiring resistance of the signal lines each electrically connected to the thin film electron emitters as well as improves planarity of each tunneling junction of the thin film electron emitters to suppress dispersion of electron emission property thereof among the pixels.

1 . An image display device, comprising: 
 a back panel including a plurality of scanning lines and a plurality of data lines on a planarized principal surface of a first insulating substrate, and a plurality of electron emitters arranged in a matrix in the vicinity of the intersections between the scanning lines and the data lines;    a front panel having phosphors respectively corresponding to the electron emitters on the planarized principal surface of a second insulating substrate, and an anode which accelerates an electron flux emitted from the electron emitters to collide with the phosphors,    a sealing frame interposed between the edges of the back panel and the front panel so as to form a vacuum enclosure together with the back panel and the front panel; and    a spacer disposed between the back panel and the front panel which maintains the distance between the two panels at a predetermined value, wherein:    a plurality of grooves are formed extending in one direction and juxtaposed in another direction intersecting perpendicularly therewith on the principal surface of the first insulating substrate forming the back panel,    the data lines include a lower layer electrode film filled in the grooves by printing and an upper layer electrode film covering the lower layer electrode film and being evaporated up to the planarized principal surface facing the grooves of the first insulating substrate; and    the electron emitters are formed on the planarized principal surface facing the grooves of the first insulating substrate of the upper layer electrode film.    
   
   
       2 . The image display device according to  claim 1 , wherein the lower layer electrode film is a thick film formed by screen printing or slit printing of silver paste, and the upper layer electrode film is a thin film of aluminum or aluminum alloy formed by deposition method.  
   
   
       3 . The image display device according to  claim 2 , wherein the electron emitters are thin film electron emitters having an aluminum or aluminum alloy thin film as a lower electrode thereof, an anodized film formed on the surface of the aluminum or aluminum alloy thin film as an insulating film thereof, and a noble metal thin film formed above the insulating film of the anodized film as an upper electrode thereof.  
   
   
       4 . The image display device according to  claim 3 , wherein the lower electrode has a planarized surface patterned after the principal surface facing the groove of the first insulating substrate.  
   
   
       5 . The image display device according to  claim 1 , wherein the upper electrode is connected to the scanning line.  
   
   
       6 . An image display device, comprising: 
 a back panel including a plurality of scanning lines and a plurality of data lines on a planarized principal surface of a first insulating substrate, and a plurality of electron emitters arranged in a matrix in the vicinity of the intersections between the scanning lines and the data lines;    a front panel having phosphors respectively corresponding to the electron emitters on the planarized principal surface of a second insulating substrate, and an anode which accelerates an electron flux emitted from the electron emitters so that it collides with the phosphors;    a sealing frame interposed between the edges of the back panel and the front panel so as to form a vacuum enclosure together with the back panel and the front panel; and    a spacer disposed between the back panel and the front panel which maintains the distance between the two panels at a predetermined value, wherein:    the data line is configured with a double layer film including a lower layer wiring film of a conductive thin film having an extension part extended into an area where one of the electron emitters is formed, and an upper layer wiring film formed by a printing method on the lower layer wiring film other than the extension part of the lower layer wiring film; and    the electron emitter includes a lower electrode which is a thin film electrode formed directly on the surface of the first insulating substrate in contact with the lower layer wiring film.    
   
   
       7 . The image display device according to  claim 6 , wherein the lower layer wiring film is a thin film of conductive material which does not lead to insulation defects due to oxidation, such as platinum, gold or iridium, and the upper layer electrode film is a thick film formed by screen printing of silver paste.  
   
   
       8 . The image display device according to  claim 7 , wherein the electron emitters are configured with thin film electron emitters each having an aluminum or aluminum alloy a part of which is formed to be superimposed on a part of the lower layer wiring film as a lower electrode thereof, an anodized film formed on the surface of the aluminum or aluminum alloy as an insulating film thereof, and a noble metal thin film formed above the insulating film of the anodized film as an upper electrode thereof.  
   
   
       9 . The image display device according to  claim 6 , wherein the lower electrode has a planarized surface patterned after the surface of the first insulating substrate.  
   
   
       10 . The image display device according to  claim 8 , wherein the upper electrode is connected to the scanning line.  
   
   
       11 . An image display device, comprising: 
 a back panel including a plurality of scanning lines and a plurality of data lines on a planarized principal surface of a first insulating substrate, and a plurality of electron emitters arranged in a matrix in the vicinity of the intersections between the scanning lines and the data lines;    a front panel having phosphors respectively corresponding to the electron emitters on the planarized principal surface of a second insulating substrate, and an anode which accelerates an electron flux emitted from the electron emitters so that it collides with the phosphors;    a sealing frame interposed between the edges of the back panel and the front panel so as to form a vacuum enclosure together with the back panel and the front panel; and    a spacer disposed between the back panel and the front panel which maintains the distance between the two panels at a predetermined value, wherein:    the data lines are formed by a wiring film formed by a printing method, and include a thin film contact electrode which extends into an electron emitter-forming part; and    the electron emitters are formed above a lower electrode, wherein a thin film electrode formed directly on the surface of the first insulating substrate in contact with the thin film contact electrode as the lower electrode thereof.    
   
   
       12 . The image display device according to  claim 11 , wherein the thin film contact electrode is a thin film of a conductive material which does not lead to insulation defects due to oxidation, such as platinum, gold or iridium, and the wiring film forming the data lines is a thick film formed by printing of silver paste.  
   
   
       13 . The image display device according to  claim 12 , wherein the electron emitters are configured with thin film electron emitters each having a thin film of aluminum or aluminum alloy formed partly superimposed on a lower layer electrode film as a lower electrode thereof, an anodizing film formed on the surface of the aluminum or aluminum alloy thin film as an insulating film thereof, and a noble metal thin film formed above the insulating film of the anodized film as an upper electrode thereof.  
   
   
       14 . The image display device according to  claim 11 , wherein the lower electrode has a planarized surface patterned after the surface of the first insulating substrate.  
   
   
       15 . The image display device according to  claim 11 , wherein the upper electrode is connected to the scanning line.  
   
   
       16 . An image display device, comprising: 
 a back panel including a plurality of electron emitters arranged in a matrix in a display region on a planarized principal surface of a first insulating substrate, and;    a front panel having phosphors respectively corresponding to the electron emitters on the planarized principal surface of a second insulating substrate, and an anode which accelerates an electron flux emitted from the electron emitters so that it collides with the phosphors;    a sealing frame interposed between the edges of the back panel and the front panel so as to form a vacuum enclosure together with the back panel and the front panel; and    a spacer disposed between the back panel and the front panel which maintains the distance between the two panels at a predetermined value, wherein:    the first insulating substrate forming the back panel has a plurality of scanning lines extending in a first direction and juxtaposed in a second direction transverse to the first direction, a plurality of data lines extending in the second direction and juxtaposed in the first direction so as to intersect with the scanning lines, and the electron emitters provided at the intersections between the scanning lines and the data lines, and    the data lines are two types of conductive materials different from each other and different in film thickness thereof.    
   
   
       17 . The image display device according to  claim 16 , wherein, at least in the display region, the two types of conductive materials of different thickness configure a double layered-structure over the whole region including areas where the electron emitters are formed.  
   
   
       18 . The image display device according to  claim 16 , wherein, the data lines formed of the two types of conductive materials are configured with a single layered-structure in areas where the electron emitters are formed, and configured with a double layered-structure in other areas except for the area, at least in the display region.  
   
   
       19 . The image display device according to  claim 16 , wherein the thicker film of the two types of conductive materials is a coating film, and the thinner film thereof is a evaporated film.  
   
   
       20 . The image display device according to  claim 17 , wherein one film of the double layered-structure in contact with the first insulating substrate is a thick coating film, and another film of the double layered-structure is evaporated to cover the coating film.  
   
   
       21 . The image display device according to  claim 18 , wherein one layer of the double layered-structure in contact with the first insulating substrate in the other area except for the area where the electron emitter is formed is a thick coating film, and another layer of the double layered-structure thinner than the one layer thereof is evaporated to be in contact with the first insulating substrate in the area where the electron emitter is formed and covers the coating film in the other area except for the area where the electron emitter is formed.  
   
   
       22 . The image display device according to  claim 20 , wherein the surface of the coating film is planarized, and the evaporated film has a planarized surface patterned after the surface of the coating film.  
   
   
       23 . The image display device according to  claim 21 , wherein the evaporated film in contact with the first insulating substrate in the area where the electron emitter is formed has a planarized surface patterned after the surface of the first insulating substrate.  
   
   
       24 . The image display device according to  claim 16 , wherein the electron emitter includes a lower electrode formed by deposition of one of the two types of conductive materials forming the data line, an insulating film laminated on the lower electrode and thinned in a part thereof which is an electron emission region emitting electrons so as to form an electron emitter opening, and an upper electrode in contact with the scanning line and covering the insulating film including the thinned part.  
   
   
       25 . The image display device according to claim  26 , wherein the spacer is disposed above the scanning line and along this scanning line.